Prefilter



FIG. 1 is a front perspective view of the prefilter;

FIG. 2 is a front view of the prefilter;

FIG. 3 is a back (rear) view of the prefilter;

FIG. 4 is a left side view of the prefilter;

FIG. 5 is a right side view of the prefilter;

FIG. 6 is a top view of the prefilter;

FIG. 7 is a bottom view of the prefilter; and,

FIG. 8 is a view showing the prefilter relationship to a potential primary filter.

The broken lines shown in the figures are for the purpose of illustrating environmental structure and form no part of the claimed design. 

CLAIM The ornamental design for a prefilter, as shown and described. 